How to format your references using the Constraints citation style

This is a short guide how to format citations and the bibliography in a manuscript for Constraints. For a complete guide how to prepare your manuscript refer to the journal's instructions to authors.

Using reference management software

Typically you don't format your citations and bibliography by hand. The easiest way is to use a reference manager:

PaperpileThe citation style is built in and you can choose it in Settings > Citation Style or Paperpile > Citation Style in Google Docs.
EndNoteFind the style here: output styles overview
Mendeley, Zotero, Papers, and othersThe style is either built in or you can download a CSL file that is supported by most references management programs.
BibTeXBibTeX syles are usually part of a LaTeX template. Check the instructions to authors if the publisher offers a LaTeX template for this journal.

Journal articles

Those examples are references to articles in scholarly journals and how they are supposed to appear in your bibliography.

Not all journals organize their published articles in volumes and issues, so these fields are optional. Some electronic journals do not provide a page range, but instead list an article identifier. In a case like this it's safe to use the article identifier instead of the page range.

A journal article with 1 author
Schaefer, B. F. (2005). Geochemistry. When do rocks become oil? Science (New York, N.Y.), 308(5726), 1267–1268.
A journal article with 2 authors
Poliakoff, M., & King, P. (2001). Phenomenal fluids. Nature, 412(6843), 125.
A journal article with 3 authors
Mavrodiev, P., Tessone, C. J., & Schweitzer, F. (2013). Quantifying the effects of social influence. Scientific reports, 3, 1360.
A journal article with 8 or more authors
Stevens, J. A., Ivison, R. J., Dunlop, J. S., Smail, I. R., Percival, W. J., Hughes, D. H., … Reuland, M. (2003). The formation of cluster elliptical galaxies as revealed by extensive star formation. Nature, 425(6955), 264–267.

Books and book chapters

Here are examples of references for authored and edited books as well as book chapters.

An authored book
Vona, L. W. (2017). Fraud Data Analytics Methodology. Hoboken, NJ: John Wiley & Sons, Inc.
An edited book
Wu, A. M. (Ed.). (2011). The Molecular Immunology of Complex Carbohydrates-3 (Vol. 705). Boston, MA: Springer US.
A chapter in an edited book
Bukovac Puvača, M., Mihelčić, G., & Tuhtan Grgić, I. (2016). Can Financial Crisis Lead to the Application of the Institute of Changed Circumstances Under Croatian Law? In B. Başoğlu (Ed.), The Effects of Financial Crises on the Binding Force of Contracts - Renegotiation, Rescission or Revision (pp. 83–99). Cham: Springer International Publishing.

Web sites

Sometimes references to web sites should appear directly in the text rather than in the bibliography. Refer to the Instructions to authors for Constraints.

Blog post
Davis, J. (2016, July 15). The UK Government Just Got Rid Of Its Climate Department. IFLScience. IFLScience. Retrieved October 30, 2018, from


This example shows the general structure used for government reports, technical reports, and scientific reports. If you can't locate the report number then it might be better to cite the report as a book. For reports it is usually not individual people that are credited as authors, but a governmental department or agency like "U. S. Food and Drug Administration" or "National Cancer Institute".

Government report
Government Accountability Office. (1970). Selected Contracting and Consulting Activities of the Office of Education (No. B-164031(1)). Washington, DC: U.S. Government Printing Office.

Theses and dissertations

Theses including Ph.D. dissertations, Master's theses or Bachelor theses follow the basic format outlined below.

Doctoral dissertation
Abedin, G. (2010). Exploring the potential of art-based education for adolescents with learning disabilities: A case study of engagement in learning through the arts (Doctoral dissertation). University of Maryland, College Park, College Park, MD.

News paper articles

Unlike scholarly journals, news papers do not usually have a volume and issue number. Instead, the full date and page number is required for a correct reference.

New York Times article
Murphy, M. J. O. (2015, November 13). The Rise of Modigliani’s Profile, and the Asking Prices for His Works. New York Times, p. C36.

In-text citations

References should be cited in the text by sequential numbers in square brackets:

This sentence cites one reference [1].
This sentence cites two references [1, 2].
This sentence cites four references [1–4].

About the journal

Full journal titleConstraints
ISSN (print)1383-7133
ISSN (online)1572-9354
ScopeArtificial Intelligence
Computational Theory and Mathematics
Discrete Mathematics and Combinatorics

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